Med-Surg Endocrine System, part 8: Hypo- vs. Hyperpituitarism & Hypophysectomy
by Cathy Parkes August 07, 2020 Updated: December 29, 2021 12 min read
In this article, we explain hypo- and hyperpituitarism, which are disorders resulting from improper pituitary gland function. We also cover the procedure called hypophysectomy, which is the removal of the pituitary gland. Knowing the pathophysiology, signs/symptoms, nursing care, and patient teaching for these two disorders will be key for Med-Surg exams and nursing practice.
What is hypopituitarism?
Hypopituitarism is a disorder where there is a deficiency in one or more of the pituitary gland hormones. If you remember from our pituitary gland overview, this master gland releases six hormones from the ANTERIOR:
- Thyroid-stimulating hormone (TSH)
- Follicle-stimulating hormone (FSH)
- Luteinizing hormone (LH)
- Adrenocorticotropic hormone (ACTH)
- Growth hormone (GH)
And two hormones from the POSTERIOR pituitary gland:
When the body has a deficiency in one or more of these eight, this can cause a lot of problems. The most common hormone deficiencies resulting in hypopituitarism are GH, FSH, and LH.
Pathophysiology of hypopituitarism
It’s most common for hypopituitarism to be caused by an issue with the pituitary gland itself. This is easy to remember. Pituitarism — pituitary gland. The patient may have a pituitary tumor, a congenital defect, or a traumatic injury to the pituitary gland.
More rarely, hypopituitarism is caused by an issue with the hypothalamus. In Endocrine Video 3 on GH, oxytocin and prolactin, Cathy teaches these endocrine hormone pathways:
- The hypothalamus releases corticotropin-releasing hormone (CRH), which causes the anterior pituitary gland to release ACTH.
- The hypothalamus produces thyrotropin-releasing hormone (TRH), which causes the anterior pituitary gland to release TSH.
- The hypothalamus releases growth hormone-releasing hormone (GHRH), which causes the anterior pituitary gland to release GH.
- The hypothalamus secretes gonadotropin-releasing hormone (GnRH), which causes the anterior pituitary gland to produce LH and FSH.
- The hypothalamus creates ADH and then it is stored in the pituitary gland to be released.
Notice that 5 out of the 8 hormones released by the pituitary gland start in the hypothalamus. It makes sense that a problem with the hypothalamus could lead to a deficiency of one of those pituitary hormones. But usually, it’s a problem with the pituitary gland.
Signs and symptoms of hypopituitarism
Hypopituitarism can result from a deficiency in one or more of eight hormones. Therefore, there are a wide variety of signs and symptoms that are possible with hypopituitarism, depending on which of the hormones’ production is affected.
The most common hormone deficiency behind hypopituitarism is GH, so delayed growth and development is a common sign.
With hypopituitarism, another common deficiency is FSH and LH. Remember that FSH and LH are responsible for the production of sex hormones estrogen, progesterone and testosterone. So, deficiencies in FSH and LH can lead to decreased sexual function, and symptoms like amenorrhea (lack of menstrual period) in women and impotence in men.
TSH is responsible for stimulating the thyroid to prompt it to produce thyroid hormones T3 and T4. So with a deficiency of TSH, the patient can then have a deficiency of T3 and T4, and may show the signs and symptoms of hypothyroidism. Thus, hypopituitarism with deficient TSH can cause secondary or tertiary hypothyroidism. Signs of hypothyroidism include weight gain, hypotension, bradycardia, lethargy, cold and intolerance.
ACTH triggers the adrenal cortex to release cortisol, aldosterone and other androgens. So when there is a deficiency in ACTH, this can lead to a deficiency of those hormones, which is known as adrenocortical insufficiency or adrenal insufficiency. Signs of adrenocortical insufficiency include fatigue, weakness, weight loss, hypoglycemia, and hyponatremia.
Lab values associated with hypopituitarism
Pituitary hormone levels will be measured, but also the target hormones. Cathy covered the expected lab values for T3, T4, and TSH in the previous video in this series.
Diagnosis of hypopituitarism
ACTH stimulation test
Remember, ACTH is one of the hormones released by the pituitary gland that causes the adrenal gland to release cortisol.
If we give a patient an injection of ACTH, and their adrenal glands successfully produce cortisol in response (determined via a blood test), we know it was a problem with the pituitary gland. The adrenal glands were just waiting for enough ACTH to function properly. So, if we know it’s a problem with the pituitary gland, that’s how we diagnose hypopituitarism.
However, if the patient gets the injection of ACTH, and they do not produce cortisol, we know it’s a problem with the adrenal glands themselves. The adrenal glands got what they needed, and were not able to complete their mission.
A CT scan or MRI can also be used to diagnose hyperpituitarism. These tests will help identify any kind of tumor or abnormality (e.g., trauma, defect) in the pituitary gland.
Treatment of hypopituitarism
Treating hyperpituitarism requires hormone replacement therapy. Sometimes this therapy may be done with the pituitary hormones, and sometimes with the target hormones.
Thyroid replacement hormones
Levothyroxine (T4) is a synthetic thyroid hormone medication for hypothyroidism. Levothyroxine can be used to treat hyperpituitarism when there is a deficiency in TSH. Since TSH is required for the thyroid to produce T3/T4, if TSH is deficient, synthetic thyroid hormones may be needed.
When a patient has hypopituitarism with GH deficiency, they may need a growth hormone replacement medication in the form of somatropin.
When a patient has hypopituitarism with ACTH deficiency, they may have a resulting deficiency in cortisol; so they may need a replacement medication for this. These are called corticosteroids or glucocorticoids and include prednisone, hydrocortisone, methylprednisolone, and dexamethasone.
Later in this series you will learn that one of the key medications given to a patient with adrenocortical insufficiency is hydrocortisone.
Dexamethasone, basically synthetic cortisol, is also used in the dexamethasone suppression test to diagnose Cushing’s syndrome.
If a patient has hypopituitarism with FSH or LH deficiency, they may also be deficient in sex hormones. Thus, they may need to take replacement sex hormone medications like estradiol or testosterone.
These medications and more are covered in our Pharmacology flashcards for nursing students.
Pathophysiology of hyperpituitarism
Hyperpituitarism usually starts with a pituitary adenoma, which is a benign tumor in the pituitary gland, or tissue hyperplasia, which is an overgrowth of tissue. Either the adenoma or the tissue usually resides in the anterior pituitary gland, compressing the brain tissue and causing increased secretion of GH, prolactin and ACTH.
Signs and symptoms of hyperpituitarism
Hyperpituitarism symptoms can include intracranial pressure due to the compressed brain tissue. This pressure can lead to headaches, nausea and vomiting.
Hyperpituitarism with growth hormone excess can result in symptoms like the hormone disorder acromegaly as well as arthralgia, which is joint pain.
Hyperpituitarism with ACTH excess results in excess cortisol, so patients may have signs and symptoms of Cushing’s disease.
Hyperpituitarism with excess prolactin can lead to symptoms of sexual dysfunction, like loss of sex drive. Because prolactin is the hormone that promotes lactation, excess prolactin can also lead to abnormal lactation.
Diagnosis of hyperpituitarism
To diagnose hyperpituitarism, the patient may need a CT scan or MRI, which will show the adenoma or tissue hyperplasia on the pituitary gland.
Treatment of hyperpituitarism
The surgery for hyperpituitarism is a hypophysectomy, which is removal of part or all of the pituitary gland.
A medication that can be used for hyperpituitarism with growth hormone or prolactin excess, is the dopamine agonist levodopa/carbidopa. Levodopa and carbidopa help to inhibit growth hormone and prolactin secretion. Need to remember levodopa/carbidopa? Check out our Pharmacology flashcards for nursing students!
Another medication for hyperpituitarism with GH excess is somatostatin, which is a medication for acromegaly. Somatostatin is actually a naturally-occurring hormone in the body that’s also known as growth hormone-inhibiting hormone.
What is a hypophysectomy?
A hypophysectomy is a brain surgery to remove all or part of the pituitary gland. A transsphenoidal hypophysectomy is when the gland is removed through the nasal cavity, which is the more common approach. Sometimes, the hypophysectomy needs to go through the oral cavity, so an incision is made under the top lip.
Nursing care following a hypophysectomy
After a hypophysectomy procedure, the patient’s nose will drain. It’s important to monitor that drainage for signs and symptoms of a cerebrospinal fluid (CSF) leak.
One sign of CSF leak is a halo sign in the drainage. This means there is clear or bloody fluid in the center of the drainage, but a yellow ring outside that drainage. If you see this halo sign, it can mean the patient has a CSF leak.
Another sign of CSF leak is if the patient complains of a headache and also indicates that their drainage tastes sweet. If you test the drainage and it’s positive for glucose, that is another sign of CSF leak and will need to be further investigated.
Patient teaching following a hypophysectomy
After a patient has a hypophysectomy, it’s important as a med-surg nurse to teach them a few things they will need to know for their recovery. While a patient is healing from their hypophysectomy, they need to avoid activities that increase intracranial pressure. Activities that increase intracranial pressure include coughing, sneezing, blowing their nose, bending at the waist, and straining during bowel movements. With these patients, you will definitely be administering stool softeners and other options to help prevent straining during bowel movements.
Following a hypophysectomy, it will be important to let your patient know that a decreased sense of smell is expected for about the first month after the procedure. It’s also recommended the patient not brush their teeth for two weeks, especially if the procedure was performed through the oral cavity. It is okay for the patient to floss and rinse their mouth.
Finally, the patient must understand that they will need lifelong hormone replacement therapy after a hypophysectomy. The pituitary gland, or part of it, is gone and it will not be producing those hormones. Hormones that may need to be replaced include cortisol in the form of a glucocorticoid, and thyroid hormones.
Cathy’s teaching on these topics is intended to help prepare you for Medical-Surgical nursing exams. The Medical-Surgical Nursing video series is intended to help RN and PN nursing students study for nursing school exams, including the ATI, HESI and NCLEX.
Okay. In this video, we are going to talk about hypopituitarism as well as hyperpituitarism, and then we'll also cover nursing care of patients who require a hypophysectomy.
So let's first talk about hypopituitarism. This is where we have a deficiency of one or more of the pituitary gland hormones that are released. And if you recall, there's a lot of different hormones that are released by the pituitary gland. This includes TSH, prolactin, FSH, LH, ACTH, GH, and then also ADH and oxytocin. So there's a lot of hormones. So when we have a deficiency of one or more of these hormones, that can cause a lot of different problems in the body.
In terms of the pathophysiology behind hypopituitarism, in most cases, it's an issue with the pituitary gland. So we have a pituitary tumor, there's some kind of congenital defect, or due to trauma, so trauma causes some damage to the pituitary gland. In some cases, it may be an issue with the hypothalamus. If you remember, the hypothalamus releases hormones that cause the pituitary gland to release hormones, so if the hypothalamus isn't doing its job, then the pituitary gland can't do its job. But in most cases, it's actually an issue with that pituitary gland.
So in terms of signs and symptoms of this condition, we're going to get a variety of signs and symptoms depending on which of the hormones is affected. In most cases, the growth hormone is affected. So when a patient has hypopituitarism, we'll often see delayed growth. Also, FSH and LH release is also affected often with this condition. So when we have decreased FSH and LH, we may see signs and symptoms such as amenorrhea in females and impotence in males. And then because we're not doing-- or not releasing as much TSH as we need to, which is thyroid-stimulating hormone, your patient may exhibit signs and symptoms of hypothyroidism, which we'll talk more about in another video. And then, lastly, we may see signs and symptoms of adrenal insufficiency because the pituitary gland is not producing enough ACTH.
So signs and symptoms of adrenal insufficiency include fatigue, weakness, weight loss, hypoglycemia, as well as hyponatremia and orthostatic hypotension.
So in terms of the labs and how we diagnose this condition, we would obviously take a look at levels of those pituitary hormones, but we also want to take a look at target hormone levels as well. And then, we're going to do something called an ACTH stimulation test.
Like we talked about, ACTH is one of the hormones released by the pituitary gland that causes the adrenal gland to release cortisol. Okay?
So if we give a patient ACTH, we give then an injection of ACTH, if there's an issue with the pituitary gland and it hasn't been producing that ACTH, it will cause the adrenal glands to be happy. They're finally getting some ACTH and they will produce their cortisol like they're supposed to.
However, if we give the patient this ACTH injection and it doesn't cause the adrenal gland to produce any cortisol, then that means there's probably an issue with the adrenal gland as opposed to the pituitary gland. So that's another test we do.
And then, we would also do a CT or MRI of the pituitary gland to try to identify any kind of tumor or abnormality in the pituitary gland.
In terms of treatment, the patient is going to require hormone replacement therapy. So they may get medications such as corticosteroids as well as thyroid replacement hormones and sex hormones and growth hormones depending on where they have those deficiencies.
Alright, now let's talk about hyperpituitarism, which is where we have oversecretion of the pituitary gland hormones. The pathophysiology behind this disorder, it typically starts with a pituitary adenoma, which is a benign tumor in the pituitary gland, or tissue hyperplasia, which is overgrowth of tissue, and either this adenoma or this tissue hyperplasia typically takes place in the anterior pituitary gland, and it compresses the brain tissue and causes increased secretion of growth hormone, prolactin, and ACTH.
So in terms of signs and symptoms of this disorder, because we have this compression of brain tissue, this can cause an increase in intercranial pressure, and this can result in symptoms such as a headache and nausea and vomiting. Also, because we have increased secretion of growth hormone, this can result in acromegaly, as well as arthralgia. So arthralgia is just a fancy name for joint pain. And with increased ACTH, this causes increased levels of cortisol, so your patient may have signs and symptoms of Cushing's disease. And we'll definitely be talking about Cushing's disease in more detail in another video. And then those increased levels of prolactin can result in sexual dysfunction as well.
So in terms of diagnosis of hyperpituitarism, we're going to do a CT or MRI of the pituitary gland, which will show this adenoma or tissue hyperplasia.
And then in terms of treatment options, surgically, we can do a hypophysectomy, which is removal of part or all of the pituitary gland. We typically go through the nasal cavity. So that is a transsphenoidal approach to the hypophysectomy. But sometimes we need to go through the oral cavity, like under the top lip or kind of there at the upper-gum level.
Medications that can be used alternatively include a dopamine agonist, which helps to inhibit growth hormone or prolactin secretion. Or we can use somatostatin for acromegaly.
Let's now talk about the nursing care and patient teaching following a hypophysectomy.
One of the main things we need to monitor for as a nurse following this procedure are for signs and symptoms of a CSF leak, or cerebrospinal fluid leak, in the drainage. So some of the signs and symptoms that may indicate there is a CSF leak include a halo sign in the drainage. So when I say halo sign. I mean that there is clear or bloody drainage in the center of the drainage, but then there is this yellow ring outside of that drainage. If you see that halo sign, that may mean that there is a CSF leak.
Other signs that may indicate a CSF leak include if the patient is complaining of a headache or is also indicating that the drainage tastes sweet. And then, if you test the drainage, and it is positive for glucose, that is also a possible sign that there is a CSF leak, and that needs to be further investigated.
In terms of patient teaching, we want to definitely teach them to avoid activities that may increase intercranial pressure. So this includes coughing, sneezing, blowing their nose, bending at the waist, and straining during bowel movements. So we are definitely going to be giving them stool softeners and things to help prevent straining during bowel movements.
In addition, you need to let your patient know that a decreased sense of smell is expected for about the first month after the procedure.
And then it is also recommended, particularly if we did the hypophysectomy through the oral cavity, that they do not brush their teeth for 2 weeks. It is okay for them to floss and rinse their mouth.
And then finally, the patient really needs to understand that lifelong hormone replacement therapy is needed because we have removed part or all of the pituitary gland. So that portion or the whole gland is not going to be producing those hormones anymore. So the patient will need to take those replacement hormones for the rest of their life.
Alright. So that is it for this video, and we will pick it up with more good endocrine information in my next video. If you have found value in this video, please leave us a comment. Make sure to like the video and subscribe to our channel. Thanks so much for watching!
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